One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Columbia can be looked at to determine when you can plant tall phlox.

Planting Calendar for Tall Phlox

Frost tolerance for tall phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Tall Phlox do ok in some cold which tells us that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant tall phlox in Columbia is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant tall phlox and expect a good harvest is probably September. You probably don't want to wait any later than that or else your tall phlox may not have a chance to really do well. You can get started a couple of weeks earlier by starting your tall phlox indoors.

Last Frost Date

In Columbia the average date of last frost happens on March 15. It might get as low as 10°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Columbia and it can change quite a bit from year to year. Since half of the time in Columbia there is a last frost after March 15 be ready to cover your tall phlox in the event of one of those late frosts.

USDA Zone Info for Columbia

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Columbia

You may be interested in your other planting guides for Columbia.